Significant improvement of thermal conductivity for AlN/LAS composite with low thermal expansion

ACS Appl. Polym. Mater.

et al. 2023

With the continuous development of electrical and electronic devices, the thermal conductivity of dielectric polymer composites within devices is becoming increasingly important. However, improving the thermal conductivity usually requires the incorporation of a large amount of filler in polymer material, which undoubtedly increases the production cost while destroying the processability and the dielectric properties of the material. In this work, an efficient heat transfer network was constructed inside the resin matrix to overcome this drawback. Using the opposite surface potentials of hexagonal boron nitride (h-BN) and polyethyleneimine (PEI) in solvent, h-BN was anchored on the surface of melamine foam (MF) by an electrostatic self-assembly technique to construct a thermal conductive skeleton with a three-dimensional open pore structure, and the corresponding epoxy (EP) composite was prepared by vacuum-assisted impregnation. This EP–MF@BN composite showed a significant increase in the heat arrival rate at an extremely low filler loading. At a h-BN loading of 2.1 wt %, the thermal conductivity of the composite reached 0.433 W/(m·K), which was 147% higher than that of the pure resin matrix. This is mainly attributed to the unique three-dimensional open-hole structure of the MF foam, which formed a three-dimensional frame structure with extremely low thermal resistance after anchoring by h-BN, thus providing a great degree of weakening of the scattering behavior during phonon transport. In addition, the transport behavior of carriers inside the composite under strong electric field conditions was analyzed in the current study. This strategy of constructing an efficient heat transfer network inside the polymer matrix provides an idea and method for the preparation of composites in the field of electrical insulation.

Section: Introductionmentioning

confidence: 99%

Preparation of Hexagonal Boron Nitride-Containing Foam with Improved Thermal Conductivity of Epoxy Resins

ACS Appl. Polym. Mater.

et al. 2023

“…[17][18][19] Thermally conductive epoxy resin (EP) materials are prepared mainly through composite filling with thermally conductive fillers. High thermal conductivity fillers (AlN, [20] BN, [21][22][23] α-Al 2 O 3 , [24] graphene, [25] boron nitride nanotubes, [26] and others) are mixed into the resin. The fillers lap each other inside the resin to form several thermally conductive pathways with low thermal resistance and thus conduct heat outward.…”

Section: Introductionmentioning

confidence: 99%

Preparation of a 3D BN network structure by a salt‐template‐assisted method filled with epoxy resin to obtain high thermal conductivity nanocomposites

et al. 2023

Polymer Composites

It is crucial to improve the thermal management capability of polymeric materials while maintaining their electrical insulating properties. Constructing thermally conductive networks with three-dimensional structures inside polymers is an efficient way to build thermally conductive pathways. A unique three-dimensional interconnected hexagonal boron nitride (h-BN) skeleton was prepared by sacrificing salt templates. The prepared three-dimensional skeleton exhibited a sponge-like structure. BN served as the main body of the thermally conductive skeleton, and polyvinylidene fluoride (PVDF) served as the binder between BN. It was subsequently supplemented with vacuum

“…Usually, fillers with high thermal conductivity, such as aluminum nitride (AlN), 15 boron nitride (BN), 16–18 alumina (Al 2 O 3 ), 19 graphene, 20,21 and diamond, 22,23 are incorporated into polymeric materials as thermally conductive fillers and the thermal conductivity of polymeric materials can be enhanced by physical blending. This approach is considered the easiest way to enhance the thermal conductivity of polymeric materials 24–27 .…”

Section: Introductionmentioning

confidence: 99%

Highly thermally conductive polymer composite enhanced by constructing a dual thermal conductivity network

et al. 2023

Polymer Composites

Constructing interconnected thermally conductive networks in a polymer matrix is essential for efficient heat transport in thermally managed materials. Thermally conductive network structures typically have meager thermal resistance, and heat transfer into the material is rapidly exported along such networks. However, increasing the thermally conductive networks inside the polymer matrix is still challenging. This paper prepared high thermal conductivity composites with “primary‐secondary” thermal conductivity networks by combining two processes: constructing three‐dimensional thermally conductive skeletal networks and physically blending fillers, using epoxy resin as the matrix. The performance test results showed that the thermal conductivity of the composites reached 1.65 W/(m K) when the boron nitride (BN) content reached 33.5 wt%, which was 842.8% and 150% higher than that of pure epoxy (EP) and composites with randomly dispersed fillers. This highly efficient heat transfer behavior is mainly due to the synergistic effect of the two‐level thermally conductive network, which weakens the scattering effect of phonons to a great extent. Also, the dielectric properties of the composite material, especially the transport of carriers inside the material under strong electric fields, were discussed in this paper. This work provides ideas and methods for preparing electrical and electronic devices applied to high power density.